May 1, 2005

20 Min Read
Everybody Loves Carbs

May 2005

Everybody Loves Carbs

By Jeanne TurnerContributing Editor

Common sense dictates that a tricycle is more stable than a bicycle. Likewise, the human diet is more healthful and balanced when carbohydrates form an essential part of the macronutrient trifecta. And when it comes to formulating successful products, removing functional, healthful carbohydrates is akin to attempting an uphill ride on a unicycle. It just isn't a good idea.

Many popular diets eliminate carbohydrates. Although they might be the food industry's current whipping boy, consumers and product developers have not abandoned carbohydrates entirely, nor would this be wise.

According to the Partnership for Essential Nutrition, Washington, D.C., the Institute of Medicine, part of the National Academy of Sciences, recently issued a recommendation that children and adults get a minimum of 130 grams of carbohydrates a day to maintain maximum brain functions, an amount more than six times that allowed by the Atkins Diet in its initial phase.

Carbohydrates serve as the most easily accessible energy source for the body's muscles and organs. Numerous studies outline the health benefits of carbohydrates. Who is unaware, for example, of the link between colon cancer prevention and whole grains? However, not only do carbohydrates serve multiple physiological purposes, such as satiety, energy, taste and psychological satisfaction, carbohydrates as an ingredient also typically create a more-functional formula and tastier finished product than substitutions.

Clearing the shelves Professionals and members of the public are starting to realize that low-carb labels can lead to confusion instead of clearing the air. Despite paper claims of "net carbs," "net effective carbs" and the like, FDA has not defined these terms. No regulations determine standards for which methods help determine these end calculations. In an effort to bring a sense of order to package claims, the Grocery Manufacturers of America, Washington, D.C., has petitioned FDA to establish new regulations for carb claims. The petition suggests guidelines including "carbohydrate-free" (less than 0.5 grams per serving) and "low carbohydrate" (less than 9 grams per serving).

Fervent interest in low-carb diets might be waning. As early as summer 2004, a survey conducted by InsightExpress, Stamford, CT, found that fewer than 10% of all Americans were following low-carb diets, such as the Atkins Diet. The survey also revealed that, of the 500 participants surveyed, those not following a reduced-carb diet did not rank carbs as the primary indicator they watch for on product labels. One participant was quoted as saying, "Diet trends come and go, and this is just another one."

Regarding labeling attributes important to consumers, those surveyed still ranked total calories and fat content the highest, followed by cholesterol, then carbohydrates, sodium and protein.

Old attitudes and new Current research indicates a movement back toward middle ground as related to carbohydrate consumption. The NPD Group, Port Washington, NY, monitors the eating habits of 11,000 U.S. consumers. While the research firm notes that each report is a snapshot of the time period data are collected, a 2005 NPD survey reports that Americans still have a healthy appetite for carbs and are actually more concerned nowadays about cutting out trans fats. Our neighbors north of the border in Canada are even less concerned about reducing carbs, with only 5% of Canadians following a low-carb diet.

A 2004 NPD report found that one out of four respondents indicated they were lowering carb intake. Yet even those significantly cutting carbs in their diets still ate an average of 128 grams of refined carbohydrates per day, a bit higher on average for males than for females. Although higher than the recommended 25 to 30 grams that low-carb and no-carb diets recommend, this level is still below the 210 grams per day consumed by an average adult. (The "refined" carbohydrate, as defined in the study, is total carbohydrates minus dietary fiber.) "People still want to lose weight, but getting people to change their behavior is very difficult to do," says Harry Balzer, vice president, NPD Group, noting that he believes low-carb dieting is a phase.

"After 10 years working with functional foods, I've found it's difficult to get people to care about what will happen to them 20 years from now," says Rhonda Witwer, business development manager of nutrition, National Starch Food Innovation, Bridgewater, NJ. She does, however, see a positive benefit resulting from low-carb dieting. For example, the ongoing wave of low-carb articles has helped consumers better define carbohydrates. "This low-carb wave, or trend, was very instrumental in helping people understand the impact of refined carbs on blood sugar levels," she says. "You can feel the impact within two to three hours from a high ingestion of simple starch or sugar. You go up and then crash. In each focus group, we get at least one person who does the glycemic curve 'wave' with their arms to explain how they feel a while after consuming a particular product." She notes that fiber, such as resistant starches, helps keep good carbs in the diet while reducing the impact on blood sugar. "You get a better energy balance throughout the day," she says, "and the insulin doesn't swing all over the place."

A resistant starch is just one of a variety of carbohydrates, and it's a wise person who can sort them out. Entire volumes discuss the various forms and chemical structures, applications, and the like. Overall, carbohydrates comprise more than 90% of the dry matter of plants. Their abundance and food value, in addition to the multiple forms available for formulation purposes, make them a popular ingredient. They exist as monosaccharides, oligosaccharides, polysaccharides, starches, gums, alginates and more. No single article can comprehensively discuss the multiple varieties and uses. However, as consumer tastes change, various products and/or functional properties demand more attention.

A sporting chance When people require quick energy, nothing suits this purpose better than some simple carbohydrates. A close analysis of a sports drink or bar reveals the essentials necessary to fuel and replenish the body during or after a workout. Almost any sports drink, regardless of brand, will have sucrose syrup and glucose-fructose syrup on the label. These simplest of sugars readily break down, enter the blood stream and feed the muscles. Sucrose does need one extra step to break down into glucose and fructose, but some formulations contain it for its taste.

Not only do these simple sugars feed muscles, they help increase stamina -- especially when consumed during crucial points in a long workout. Try running a marathon, or even half-marathon, without a carbohydrate to pump-up the body. Most of us try to complete a "marathon" of activities during a long day at school or at work and, just like the long-distance runner, we need these essential carbohydrates to fuel us.

Energy benefits can come from other traditional source of carbohydrates. "Wheat-based foods, predominantly based on carbs, are the preferred energy source for the brain and the most efficient energy source," say Lori Sachau, R.D., director of nutrition and outreach, the Wheat Foods Council, Parker, CO. "Carbohydrates operate as a complex mechanism to keep glucose in check, and the average consumer should keep their consumption in the range of 45% to 60% of daily calories."

Sachau explained that a diet that eliminates carbs entirely starts to harm the body as it starts breaking down protein tissues and fats and forming ketones. "The body can function on ketones, but they exist as a backup system, operating to protect the body against starvation," she says. "Too many ketones in your system upset the acid balance in the body, and it won't function correctly."

Folic acid in fortified flour, which contains more than twice the amount of whole grains, also needs consideration. "Whole-grain flour is getting a lot of attention right now, but the fortification message needs to be understood as well," Sachau says. "And some consumers, despite the health benefits of whole grains, still will not want to eat them."

The sweeter side of life The bad rap given lately to high-fructose corn syrup (HFCS) might not be so well deserved. In terms of the claims that HFCS has contributed to the rise of obesity in this country, John S. White, Ph.D., spokesman for the Corn Refiners Association, Washington, D.C., writes in a 2004 white paper, "This argument is at odds with the rising obesity in Europe and Mexico, geographic areas where HCFS sales are minor in comparison with sucrose."

In addition, White points out that metabolically, sucrose and HFCS are absorbed in the same manner. The sweetness profile is very similar as well, with HFCS -55 and -42 at 99% and 92% the level of sucrose, respectively. Delivered in liquid form, HFCS offers pumpability and readily blends with other liquid ingredients. Especially in carbonated-beverage formulations, HFCS is stable under low pH and the high temperatures that sometimes occur during storage. These attributes help provide a stable sweetness level and flavor profile. "They have largely replaced sugar in applications where they are now, because the liquid nature of the product is less labor-intensive than using bags of sugar," he says.

For formulators who prefer a bulk sweetener that stimulates a different type of bodily reaction in terms of insulin response, this category provides multiple choices, depending on the application. The glycemic index (GI) ranks foods based on their effect on blood-sugar levels. "Lactose, for example, has a glycemic index of 46, as compared to 60 for sucrose and 100 for glucose," notes Sharon Gerdes, technical support consultant, Dairy Management Inc.(TM) in Rosemont, IL.

In fact, studies have shown that low-GI diets actually help improve glycemic control in individuals with diabetes. Diets based on low-fat foods that produce a low glycemic response might enhance weight control because they promote satiety, minimize postprandial insulin secretion and maintain insulin sensitivity. "Lactose is also a natural sweetener, which may appeal to parents who want to limit their children's intake of artificial sweeteners," continues Gerdes.

Because of its slow transit time through the digestive system, some undigested lactose will reach the colon, where it stimulates the growth of beneficial lactic-acid bacteria. Lactose also is the starting material for various prebiotics, such as lactulose and lactitol.

The bulk of the matter Maltodextrin possesses multiple functional talents. One traditional use is as a bulking agent. Processors derive maltodextrins from corn, potato, rice or tapioca. The biggest factor in functionality related to a maltodextrin is its dextrose equivalency, or DE, and the functional characteristics a maltodextrin supplies are related directly to its DE.

As a bulking agent, these carbohydrates can function in a liquid or dry system. For example, bulk density is extremely important in a dry mix, while in a liquid system, viscosity might be a more-important consideration. Taste is primary, and among maltodextrins, the potato and rice versions have the blandest flavor profiles, allowing the full flavor of the formulation to reach its potential without interference. Additionally, most maltodextrins possess low sweetness levels.

These types of ingredients also hold up well under high heat, and can withstand a wide pH range and more stressful processing conditions like shear. These characteristics enable maltodextrin use in a relatively wide range of applications. However, most carbohydrates used as bulking agents can help formulators extend more-expensive ingredients.

Specialty carbohydrate bulking agents can provide advantages in specific applications. For example, Penford Food Ingredients, Englewood, CO, recently introduced a non-GMO dextrose with spherical particles for superior bonding and structural integrity in tableting operations. In a hard candy or mint, the particles allow better color and flavor dispersion throughout the tablet. In addition, improved tablet integrity is achieved using lower mechanical pressure.

The improved tablet structure makes possible unique shapes and firmer sidewalls that allow manufacturers to imprint a logo on the candy tablet. A faster dissolution time, compared to standard dextrose, applies for uses in dry drink mixes.

Texturize me Polysaccharides predominate in their natural state in our known universe -- scientists estimate that more than 90% of the carbohydrate mass in nature takes some polysaccharide form. These polymers of monosaccharides possess a high molecular weight compared to other carbohydrates.

Most food scientists think of starches as hydrocolloids. Some natural-source ingredients, such as guar gum, can fluctuate in both supply and quality depending on local weather patterns where harvested. Further-processed starches, on the other hand, provide a level of quality control and can be blended into custom formulations to provide certain desirable functional attributes.

For example, by itself, guar gum has extremely high viscosity. When blended with other starches, designers can temper or modify the viscosity according to desired product specifications. When mixed with substances such as xanthan or locust bean gum, the viscosity increases, so less is required of each individual ingredient.

Starches and hydrocolloids can prevent ice crystals from forming in ice cream, or thicken pastry filling to prevent it from weeping into the surrounding crust. They can act as fat substitutes, to help mimic the mouthfeel of a higher fat product, or provide a wide range of additional functional benefits. Overall, the rheological properties of a starch depend upon the type of starch, its size, shape and granular integrity.

Product developers use hydrocolloid polysaccharides known as gums primarily to thicken or gel aqueous solutions or to modify the flow properties and textures of liquid food and beverage products. Highly effective, the general usage level ranges only from 0.25% to 0.50%. This ability to create high viscosity at low levels makes these ingredients popular in industrial formulations.

Deliberate depolymerization helps create a wide range of viscosity grades for most gums to suit formulators' needs. Other factors that designers need to take into consideration when selecting the proper hydrocolloid are the cost or functionality needed to achieve the desired viscosity, system pH, processing temperatures and times at each processing stage, and storage temperature.

As an added benefit, hydrocolloid gels can enhance flavor and sweetness of food products because the thicker nature of the product means that the food is held in the mouth longer. However, this can be a double-edge sword, depending on the level of viscosity. As viscosity increases, perceived intensity of flavor and sweetness is suppressed because greater viscosity means reduced rates of transport of fresh flavor or sweetener to the taste buds. Increased shear, which thins the solution rheology, will result in less flavor and/or taste suppression.

Product designers can also make use of both gums and starches to create a desired effect in some products. "Combining a starch and gum in an application may result in an additive or synergistic effect to provide enhanced viscosity, particulate suspension, rheological properties and moisture binding in a particular application," says Celeste Sullivan, senior applications scientist, Grain Processing Corporation (GPC), Muscatine, IA, noting that these combinations might result in lower use levels, reducing the need for flavor masking. "One example of where these combinations are often seen is in the salad-dressing market."

Resistance isn't futile Resistant starches contribute fibrous characteristics to countless formulations. According to Witwer, National Starch's resistant starch belongs to a category of physiologically defined ingredients. This naturally derived ingredient, she says, is distinct from a brand-new category of chemically developed resistant starches that do not offer the same benefits.

Various categories help define resistant starches. This particular resistant starch is an RS2, or natural starch granule. When a plant makes starch, it uses this as a way of storing glucose and it packs it into tight granules. Raw potatoes, high-amylose corn and green bananas are all natural sources of RS2. The interesting thing is cooking a potato (exposing the starch to heat), transforms it from an RS2 to a highly digestible form. When the potato cools down, the starch retrogrades -- the chains inside the starch line up and crystallize; this forms an RS3 type of starch typical to pasta and some types of corn-extruded cereals.

Product designers can replace as much as 50% or 60% of the flour in baked goods. This fiber content significantly reduces the impact on blood sugar. However, large quantities of resistant starch can impact product taste and texture. For a typical baked good, the replacement levels more commonly might range from 10% to 40%, depending on the label claim the manufacturer wants -- a "good" source of fiber, or a "high" source of fiber. Witwer points out that sometimes these label claims are more easily achieved using a combination of grains. The most-popular applications for this type of resistant starch include pizza crust and nutritional bars, but they even find their way into gummy-style candies and a nutritional beverage in Australia.

In cereals, Witwer says, it "contributes to enhanced crisping and bowl life, in addition to the benefit of the added fiber." She notes that when substituting for flour in many types of baked goods, formulators typically have to replace some of the gluten needed for proper structure.

A perfect couple A rich-brown color defines comfort food for many, including a crusty load of bread or thick, golden-brown gravy. This nonenzymatic browning, known as the Maillard reaction, involves the reaction of carbonyl groups or sugars (carbohydrates) and amino acids, or free amino groups.

Lactose, for example, is a reducing sugar, and in baked goods it contributes to Maillard browning, which gives the finished products not only an appealing color, but a pleasant odor as well. Food formulators may use straight lactose or add lactose in the form of dry, sweet whey or whey permeate. These very cost-effective ingredients can be used in a variety of bakery formulations. According to Gerdes, lactose is especially popular in breads because it is not fermented by yeast, and thus is available to brown in the oven. Lactose also improves the kneading characteristics of the dough, making it more elastic and increases loaf volume.

According to White, HFCS plays an important role in baked goods. Not only does it contribute to flavor enhancement, but its fructose-glucose composition also helps with fermentability. "The microorganisms fermenting it do not have to break the sucrose or other more-complex bonds," he says. These monosaccharides come in handy for enhancing the Maillard reaction and providing superior browning and baked flavor.

Also, because HFCS does not crystallize, in products that need to retain a softer texture, such as a soft cookie, HFCS yields a more-pliable product. HFCS's greater osmotic effect binds moisture better than sucrose, helping extend a product's shelf life and improve humectancy.

Mimicry: the best form of "fattery" The humble, yet amazing, potato provides a carbohydrate that can play a role in fat mimetics. For example, Penford Food Ingredients offers formulators a starch product that mimics fat.

This ingredient is a prehydrated, structured, starch-gel product that can deliver significant calorie and fat reduction while preserving the original flavor and texture of a meat product. "If you look at it side by side with ground fat, it looks the same," says Michael Wempen, dextrose sales manager for the company. "It simply is a gelatinized and cooled starch. No one else has it," he says. "It runs through the grinder and takes on the look, feel and texture of fat."

Depending on the desired level of fat reduction, applications could use 12% in formulation without additional starches, or a higher percentage in a dual-starch system. Typical applications include reduced-fat meat and poultry products, such as chicken nuggets, sausage, hamburger or coarse-ground, emulsified meat products. Because it stems from potato starch -- a bland substance -- it has no flavor, and absorbs the flavor of the meat. Its potato-starch origin also serves it well in the school foodservice market, because potatoes generally do not the cause allergenic reactions.

The dairy-derived starch, lactose, can also help product designers reduce shortening and sugar requirements in breads, pastries and sweet rolls. Lactose also helps to provide shorter, flakier and more-tender pie crusts. Lactose increases mixing tolerance in cookies and eases release from rotary cookie dyes.

Moisture control An effective humectant helps bind and retain moisture. For example, it helps baked goods stay moist and soft over an extended shelf life. Polyols, known primarily as bulk sweeteners that lower sugar levels and calories, offer this added functional property.

Polyols are sugar alcohols produced by fermenting different carbohydrates with wheat and maize, the main raw ingredients. Polyols are found in nature in diverse substances, ranging from almond shells to birch bark. However, processors generally derive commercially available polyols through a chemical process that uses corn; lactitol comes from milk.

Marie Kozlowski, polyol sales specialist for Cargill Food & Pharma Specialties, Minneapolis, says that of the seven different types of polyols, erythritol is the only natural polyol made from yeast fermentation. This is the least hygroscopic of all polyols, due to its small particle size. It is comprised of four carbon molecules, so many molecules can pack into a small space. This is why it lends good humectant properties to baking applications. "As nutritional needs are changing in our society, polyols are really changing their profiles," she says. "They can help both with formulating for a low glycemic index and lower calories, while providing some good functionality."

Gazing into the crystal ball What does the future hold for the much-maligned carbohydrate? As an ingredient, the future actually looks quite bright. Are Americans continually snacking on chicken breast, celery stalks or other zero-net-carbohydrate concoctions? Rarely.

A recent NPD Foodworld SnackTrack® study revealed that the top-five foods consumed during a snack occasion, whether at home or away, was headed up by salty snacks. Other favorites were fruit, frozen ice cream treats and novelties, and cookies. In fifth place were candy and gum. (The candy and/or gum category did not include power or energy bars.) This snapshot of just one food category, snacks, should give processors a glimpse of our future relationship with carbohydrates -- it will be a cozy one.

And within all the varied categories of polysaccharides, starches and the like, the best strategy for achieving formulation success is a close working partnership with a carbohydrate ingredient supplier. One starch might suffice in a poultry system, for example, while another would better suit a hot dog.

In terms of carbohydrates and weight loss, the message might turn from good and bad carbohydrates to good, better and best choices, depending on the outcome desired. In fact, a study released in Oct. 2004 by National Starch Food Innovation suggested that certain carbohydrate choices can help in the battle of the bulge. The study revealed that consumption of products featuring low levels of Hi-Maize(TM) resistant starch in the morning increased fat burning during the day by 23%.

"Most people think of refined flours and sugar when they think of carbohydrates," says Witwer. "Everybody assumed they were all the same. Hence the USDA food guide pyramid stacked them all at the bottom. This won't be the case in the future." On that point, the vision in our crystal ball seems pretty clear.    

Jeanne Turner is a freelance writer with more than 10 years of experience writing about the functional properties of food ingredients.

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